Muscle rigidity is one of the most common causes of muscle pain. It’s characterized by the inability of the muscles to relax normally. The condition can affect any of the muscles in the body, causing sharp pain that makes it difficult to move. Muscle rigidity is also known as muscle tension, rigor, or stiffness.

Causes of Muscle Rigidity
There are muscles all over your body. When you need to move a particular part of your body, your brain sends a nerve signal to the muscles located in that body part. This causes the muscles to tighten, or contract. Muscles can contract a little bit or a lot, depending on the type of signal the brain sends. After contracting, the muscles relax until the next time you need to use them.

Muscle rigidity occurs when a muscle or groups of muscles stays contracted or partly contracted for an extended period. The brain continues to send nerve signals telling the muscle to contract even when the muscle is no longer needed for movement. This can sometimes last for several hours or days. The longer your muscle remains contracted, the more pain you’ll feel.

Muscle rigidity is often triggered by stress. Stress can adversely affect the body’s nervous system, including its nerves and how they function. The nervous system may respond to stress by putting additional pressure on the blood vessels, which results in reduced blood flow to the muscles.

Home Remedies
Home remedies are usually effective in treating muscle rigidity caused by minor injuries, stress, or overuse. They can include the following:
-- Apply a warm compress or heating pad to the affected muscle to help relax rigid muscles.
-- Gently stretch your stiff muscle to help relax it.
-- Avoid strenuous activity that may trigger the muscle to become rigid again.
-- Encourage the muscles to relax using massage, yoga, or tai chi.